I. Field
The present disclosure relates generally to communication, and more specifically to techniques for positioning user equipments (UEs) in a wireless communication network.
II. Background
Wireless communication networks are widely deployed to provide various communication content such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.
A wireless communication network may include a number of base stations that can support communication for a number of UEs. A UE may communicate with a base station via the downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.
It may be desirable, or necessary, to know the location of a UE. The terms “location” and “position” are synonymous and are used interchangeably herein. If the UE has Global Positioning System (GPS) capability, then the UE may receive and process signals from GPS satellites to obtain time measurements, which may be converted to pseudo-ranges. The location of the UE may then be accurately estimated based on pseudo-ranges for a sufficient number of satellites and their known locations. However, the UE may not have GPS capability, or may have GPS capability but may encounter difficulty in receiving GPS signals due to its environment. It may be desirable to obtain a location estimate for the UE in such scenarios.